Surgically-implanted heart valve prostheses of the mechanical type have extended the life expectancy of many patients who had defective natural valves. Such prostheses are essentially check valves having a valve body that provides a blood flow passageway and an occluder, in the form of either one or two leaflets, that shifts to alternatively open the passageway, in response to blood flow in the circulation direction, and close the passageway, to prevent regurgitation of blood therethrough when the pumping action of the heart produces a localized back pressure. The heart valve body is generally formed from a rigid material, such as metal or pyrolytic carbon, and is commonly provided with a suture ring permanently secured thereto for attaching the valve body to the tissues of the heart.
To facilitate the implantation of heart valve prostheses, specialized holders have been developed that enable a surgeon to precisely position the heart valve and the suture ring within the heart passageway and to securely hold the assembly in place until suturing has been effected. It is desirable that such holders provide a quick, sure release of the sutured valve without placing undue strain on the tissue sutured to the prosthesis, and also that the holder be re-engageable with the valve body after the release thereof if repositioning of the valve is required.
For convenience, prostheses and their associated holders are frequently assembled by the manufacturer and shipped singly in sterile enclosures. During shipment of the assembly of the heart valve and holder, it is desirable that the assembly be stably held within the enclosure, and, more particularly, that the motion of the valve leaflets be sufficiently restricted so as to prevent any unnecessary load on the prosthesis due to the shifting of the leaflets during transportation.